Galapagos Islands: Major Landscapes and Ecosystems

Report prepared by Meaghan Leslie-Gottschligg and Scott Grimsrud, students in BCIT's Fish, Wildlife and Recreation Program.

The islands of the Galapagos have seven zones, each with its own climate. Between the dry lowland areas near the ocean, to the high, wet areas near the tops of volcanoes, the flora changes dramatically.

The Coastal Zone

This zone is highly variable within and throughout the islands, ranging from salt tolerant mangroves to beaches with vines, grasses, and shrubs. Its evergreen plant community is highly adapted to dispersal by sea, making very few of the species endemic.

The Arid Zone

As the most extensive vegetated ecosystem on the islands, the semi-desert forest of the arid zone contains deciduous trees and shrubs (many of which are endemic). This zone can reach the top of low lying islands. Common plants are the prickly pear cacti species and Palo Santo trees. Occasional mists supply moisture to the abundant, drought-tolerant lichens in this zone.

The Transition Zone

As you would expect from its name, the Transition zone is an area between the Arid and Scalesia zones that shares characteristics of both. The mainly deciduous forest of this ecosystem is far more dense and diverse than the Arid zone due to an increase in moisture. Some less drought-tolerant plant species, such as Pega-pega begin to appear.

The Scalesia Zone

The Scalesia zone is a lush, dense, cloudforest, fed moisture by the garua mists. This ecosystem only occurs on the higher islands and because of its fertility and productivity, has been extensively damaged by agricultural and ranching practices. The characteristic plant species of this zone are, of course, those of the genus Scalesia which are members of the daisy family (Compositae). All are woody shrubs except for Scalesia pedunclulata, which is the only member that has evolved into a large tree. The diverse Scalesia zone has many endemic species.

The Brown Zone

At the point where the land begins to stick up out of the mists, the Brown zone begins. The ground in this zone does not retain as much moisture as the Scalesia zone, causing a reduction in plant biomass. Common plants in this open forest are cat's-claw (trees and shrubs), brown lichens and liverworts. Trees are covered with epiphytes, mosses and ferns. In the dry season, most of the vegetation turns brown, giving the zone its name. Sadly, this zone has all but disappeared due to colonization by man.

The Miconia Zone

The Miconia zone is characterized by dense growth of the shrub Micronia robinsoniana. This zone can be found on the southern slopes of San Cristobal and Santa Cruz islands. There are no native trees in this zone but ferns and liverworts are abundant. Since people have begun farming on the islands, cattle have grazed the Miconia to the point where it has become the most endangered plant on the islands.

The Pampa Zone

The Pampa zone is the coolest and wettest one in the Galapagos, receiving as much as 2.5 m of rain in a year. As there are no trees or shrubs in this zone, the plant community consists of ferns (including the Galapagos tree fern), grasses, and sedges. Where people have colonized, this landscape is used as farmland and cattle pasture.